Selective alkylation of β-anhydroicaritine and their biological evaluation on anticancer.

A convenient and selective alkylation of icaritin has been developed. The methodology involved initial formation of β-anhydroicaritine ( 3 ) under acidic conditions followed by selective methylation at the C-3 position and then alkylation at C-5 position. Several alkylated β-anhydroicaritine derivatives were synthesised using this methodology. These newly synthesised derivatives, especially the compounds 5b , 5c and 5j , significantly suppressed cell proliferation when tested against cancer cell lines in vitro . Compound 5j (R = Bn) exhibited a competitive inhibition against MCF7 in vivo compared to tamoxifen.